The invention generally relates to electrical connectors, and more specifically, to surface mounted electrical connectors that can be mounted on the surfaces of printed circuit boards by automated surface component mounting equipment, capable of sequentially picking up the electrical connectors, one at a time, and transferring them from a pick-up station to a mounting station for accurately mounting on a printed circuit board.
Numerous electrical connector designs have been proposed for mounting on printed circuit boards. Many of these are for pins or posts that are formed by stamping flat sheet stock. In many cases, the pins or posts are initially connected to each other by a carrier strip to allow automated mounting on a printed circuit board. The aforementioned pins or posts take on different shapes, including relatively flat shapes as shown in U.S. Pat. No. 5,073,132. Thin flat posts are shown in U.S. Pat. No. 3,864,014. Box-type male connectors are illustrated in U.S. Pat. No. 3,375,486. Relatively large cross-section pins are also disclosed in U.S. Pat. Nos. 4,017,142 and 3,428,934.
In U.S. Pat. Nos. 4,395,087 and 3,663,931, substantially square, solid pins are utilized for the electrical contacts. In the '087 patent, the pins are mounted on a carrier strip while in the '931 patent a unitary pin is shown formed integrally with a socket contact, presumably formed out of stamped material. In U.S. Pat. No. 4,369,572, a substantially solid rectangular pin is shown welded to the carrier strip. However, none of the known designs disclose pin connectors formed from flat sheet stock adapted or suitable for surface mounting on a printed circuit board.
It is also known to provide single loose surface mount pin terminals each packaged in individual plastic pockets P carried by a plastic pocket carrier or tape T, as shown in FIG. 17 tape. However, the aforementioned approach has a number of problems and has not found wide acceptance in the industry. To begin with, the additional plastic pockets or envelopes P have increased the per unit costs of the surface mounted components. Additionally, because the surface mounted pins are contained within a normally oversized pocket or enclosure, the components have at least some degree of freedom of movement therein and this has made it difficult and impractical to precisely align the components at the pick-up stations of the automatic pick-and-place equipment with the vacuum nozzles used for this purpose, notwithstanding the sprocket or pilot holes H intended to accurately align the pins. Such machinery demands very accurate alignment of the parts during pick-up and even small misalignments from the required positions may cause damage to the parts and/or to the nozzles themselves.
In view of the foregoing, although significant advancements have been made in the design and use of pick and place equipment, such machinery has primarily been used to pick and place components that have a sufficiently large surface to provide a suction area for the nozzles. As such, such machinery has primarily been used to pick and place transistors, ICs, capacitors, and numerous other electrical components that provide the requisite surfaces. However, because electrical posts, test points, IDC's and other electrical receptacles have not always exhibited the requisite geometries suitable for pick and place equipment, it has not always been possible to automate the mounting of such components utilizing surface mount technology.
Until now, therefore, surface mount posts were packaged in header form utilizing a plastic body to hold a row of components and placed on the board by a pick-and-place robot. If there was a need for test points, tabs, IDCs or any other type of single terminal, the board and the manufacturing process had to be a combination of surface mount technology and through-hole technology, because those terminals were available for through-hole technology only.